Oyster reefs in Australia are Critically Endangered, and >99% and 92% of flat oyster (Ostrea angasi) and Sydney rock oyster (SRO, Saccostrea glomerata) habitats have been lost since colonisation due to overharvesting and European land use practices. The majority of the degradation occurred during the late 1800s and early 1900s, so the once iconic ecosystem has been largely lost to living human memory. Increasing public focus on restoration increases the need to monitor and project recovery success. The Green Status of Ecosystems (GSE) is a framework under development by the IUCN to measure the past, current and future recovery of ecosystems from degradation caused by human activities, relative to a "fully recovered” reference state. In this project, we perform a case study GSE assessment of the southern and eastern Australian oyster reefs. We compare the past, present, and future statuses of the ecosystem to the baseline to evaluate conservation impact and recovery potential. Our results show that the recovery score of the oyster reefs is increasing due to restoration, but they remain in critical condition. These results will inform and motivate oyster reef restoration efforts as well as inform the development of standardised GSE methods.